CN104595435B - Eight shift transmissions - Google Patents

Abstract

An eight-speed transmission, which mainly includes an input shaft, an output shaft, a planetary gear row, a connecting member and a torque transmission device. A plurality of planetary gears, ring gears, said torque transmission devices including clutches and brakes, each torque transmission device can selectively engage or fix one of the sun gear, planet carrier, ring gear and four connecting members , can be selectively engaged in a combination of at least two so that eight forward speed ratios and one reverse speed ratio can be established between the input shaft and the output shaft. The forward gear is five reduction gears, one Direct and two overdrive gears. The gear of the present invention has small modulus, compact structure, small volume and light weight, and the total speed range is 8.73.

Description

eight speed transmission

technical field

The invention belongs to the technical field of vehicle transmission, in particular to a transmission.

Background technique

A typical multi-speed transmission uses a combination of friction clutches, planetary gearing, and fixed interconnections to achieve multiple gear ratios. The number and physical arrangement of planetary gear sets is usually dictated by packaging, cost and desired speed ratios. While current transmissions fulfill their intended purpose, there is a virtually constant need for new and improved transmission configurations that improve primarily performance (especially in terms of ratio range, responsiveness and smoothness) perspective) and packaging (mainly reduced size and weight) improvements are required to improve cost-effective, compact multi-speed transmissions.

Contents of the invention

The object of the present invention is to provide an eight-speed transmission with compact structure, light weight, and the ability to expand the transmission ratio range.

The invention mainly includes an input shaft, an output shaft, a planetary gear row, a connecting member and a torque transmission device, and these members are all arranged in the transmission case. The planetary gear row includes a first planetary gear row, a second planetary gear row, a third planetary gear row and a fourth planetary gear row, and each planetary gear row includes a sun gear, a planet carrier, a planetary gear and a ring gear; the The connecting member includes a first connecting member, a second connecting member, a third connecting member and a fourth connecting member; the torque transmitting device includes a first clutch, a second clutch, a first brake, a second brake, a third brake and a fourth Four brakes.

the first connecting member interconnects the sun gear of the first planet row and the sun gear of the second planet row;

The second connecting member continuously interconnects the ring gear of the first planetary row, the carrier of the second planetary row and the ring gear of the third planetary row; the third connecting member connects the second planetary row The ring gear of the fourth planet row is interconnected with the planet carrier of the fourth planet row; the fourth connecting member interconnects the planet carrier of the third planet row with the ring gear of the fourth planet row.

Each torque transmitting device is capable of selectively engaging or securing one of the sun gear, planet carrier, ring gear and four connecting members, and wherein the torque transmitting devices are selectively engageable in combinations of at least two for Eight forward speed ratios and one reverse speed ratio can be established between said input and output shafts.

The first clutch interconnects the input shaft and a second connecting member, and the second clutch interconnects the input shaft and first connecting member.

The first brake interconnects the first connecting member and the transmission housing, the second brake interconnects the planet carrier in the first planet row with the transmission housing, and the third brake interconnects the The second connecting member interconnects the transmission housing, and the fourth brake interconnects the sun gear of the fourth planetary row with the transmission housing.

The sun gear of the third planet row is always connected with the input shaft, and the planet carrier of the fourth planet row is connected with the output shaft.

Compared with the prior art, the present invention has the following advantages:

1. The modulus of the gear is small, the structure is compact, the weight is light, and it is easy to arrange on the car;

2. The number of torque transmission components is reduced. The eight-speed transmission only uses six torque transmission components, which is the same as the number of torque transmission components used in the commonly used Chrysler six-speed transmission. Minimize the volume of the transmission;

3. The control of each gear only needs two coupling members, while the control of each gear of the classic ZF 8-speed transmission requires three coupling members, so the control is relatively simple;

4. The total transmission range of 8.73 is wider than the transmission range of 7.37 of the classic ZF 8-speed transmission and 6.71 of the Lexus LS460 transmission. The speed ratio steps between the transmission ratios of each gear meet the requirements of the transmission.

Description of drawings

Fig. 1 is a schematic diagram of the arrangement and connection of each component of the eight-speed transmission of the present invention.

In the figure: 1—first planetary ring gear, 2—first planetary planetary gear, 3—first planetary planet carrier, 4—first planetary sun gear, 5—second planetary ring gear, 6— The second planetary row planetary gear, 7—the second planetary row planet carrier, 8—the second planetary row sun gear, 9—the third planetary row ring gear, 10—the third planetary row planetary gear, 11—the third planetary row planet Frame, 12—third planetary sun gear, 13—fourth planetary ring gear, 14—fourth planetary planetary gear, 15—fourth planetary planet carrier, 16—fourth planetary sun gear, 17—first A connecting member, 18—second connecting member, 19—third connecting member, 20—fourth connecting member, 21—transmission housing, 22—input shaft, 23—output shaft, C1—first clutch, C2—first Two clutches, B1—the first brake, B2—the second brake, B3—the third brake, B4—the fourth brake.

detailed description

In the schematic diagram of the eight-speed transmission shown in Figure 1, all components are arranged in the transmission housing, and the planetary gears 2, 6, 10, and 14 in each planetary row pass through the sun gear and the ring gear in the same planetary row respectively. The gear pairs mesh with each other. The first connecting member 17 continuously interconnects the first planetary ring gear 1 , the second planetary carrier 7 and the third planetary ring gear 9 ; the second connecting member 18 connects the first planetary sun gear 4 and the third planetary ring gear 9 . The second planetary sun gear 8 is interconnected; the third connecting member 19 interconnects the second planetary ring gear 5 and the fourth planetary carrier 14; the fourth connecting member 20 connects the third planetary carrier 11 with the fourth The planetary ring gears 13 are interconnected.

Each torque transmitting device is capable of selectively engaging or securing one of the sun gear, planet carrier, ring gear and four connecting members, and wherein the torque transmitting devices are selectively engageable in combinations of at least two for Eight forward speed ratios and one reverse speed ratio can be established between said input and output shafts.

A first clutch C1 interconnects the input shaft 22 with the first connecting member 17 and a second clutch C2 interconnects said input shaft 22 with the second connecting member 18 .

The first brake B1 interconnects the second connecting member 18 with the transmission housing 21, the second brake B2 interconnects the first planetary carrier 3 with the transmission housing 21, and the third brake B3 interconnects the first connecting member 17 and the transmission. The housing 21 is interconnected, and the fourth brake interconnects the fourth planetary sun gear 16 and the transmission housing 21 .

The third planetary sun gear 12 is always connected to the input shaft 22 .

The fourth planet carrier 15 is connected with the output shaft 23 .

The input shaft is always connected to the engine or the turbine of the torque converter. The output shaft is connected to the next stage reducer.

A first brake B1 is selectively engageable to connect the second connecting member 18 with the transmission housing 21 for the purpose of preventing rotation of the first connecting member 18 relative to the transmission housing 21 . The second brake B2 is selectively engageable to connect the first planetary row member 3 with the transmission housing 21 in order to prevent the rotation of the first planetary row member 3 relative to the transmission housing 21 . The third brake B3 is selectively engageable to connect the first connecting member 17 with the transmission housing 21 in order to prevent rotation of the first connecting member 17 relative to the transmission housing 21 . A fourth brake B4 is selectively engageable to connect the fourth planetary row member 16 with the transmission housing 21 for the purpose of preventing rotation of the four planetary row members 16 relative to the transmission housing 21 .

The transmission can realize eight forward speed ratios and one reverse speed ratio. The speed ratios for each gear are achieved by engaging the two torque transmitting devices. Table 1 shows the different combinations of torque transmitting members engaged to achieve each gear state. Table 1 also gives the value of the transmission ratio of each gear and the value of the speed ratio step between two adjacent gears. We can construct a new transmission ratio by selecting the number of teeth of the planetary gear, the diameter of the gear and the structure of the gear within the range allowed by the gear characteristic parameters.

The working process of each gear:

To establish reverse gear, the second clutch C2 and the third brake B3 are engaged. Specifically, the second clutch C2 is engaged to connect the input shaft 22 with the second connecting member 18 . The third brake B3 is engaged to connect the first connecting member 17 and the transmission housing 21 in order to prevent rotation of the first connecting member 17 relative to the transmission housing 21 . As a result, a reverse gear ratio is established between the input shaft 22 and the output shaft 23 .

First gear is established, third brake B3 and fourth brake B4 are engaged. Specifically, the third brake B3 is engaged to connect the first connecting member 17 and the transmission housing 21 in order to prevent rotation of the first connecting member 17 relative to the transmission housing 21 . A fourth brake B4 is engaged to connect the fourth planetary member sun gear 16 with the transmission housing 21 in order to prevent rotation of the fourth planetary row member sun gear 16 relative to the transmission housing 21 . As a result, a gear ratio of first gear is established between the input shaft 22 and the output shaft 23 .

With the establishment of second gear, the second brake B2 and the fourth brake B4 are engaged. Specifically, the second brake B2 is engaged to connect the first planetary carrier 3 and the transmission housing 21 , in order to prevent the first planetary carrier 3 from rotating relative to the transmission housing 21 . A fourth brake B4 is engaged to connect the fourth planetary row member sun gear 16 with the transmission housing 21 in order to prevent rotation of the fourth planetary row member sun gear 16 relative to the transmission housing 21 . As a result, a transmission ratio of second gear is established between the input shaft 22 and the output shaft 23 .

With the establishment of third gear, the first brake B1 and the fourth brake B4 are engaged. Specifically, the first brake B1 is engaged to connect the second connecting member 18 with the transmission housing 21 in order to prevent rotation of the second connecting member 18 relative to the transmission housing 21 . A fourth brake B4 is engaged to connect the fourth planetary member sun gear 16 with the transmission housing 21 in order to prevent rotation of the fourth planetary row member sun gear 16 relative to the transmission housing 21 . As a result, a transmission ratio of third gear is established between the input shaft 22 and the output shaft 23 .

The fourth gear is established, the second clutch C2 and the fourth brake B4 are engaged. Specifically, the second clutch C2 is engaged to connect the input shaft 22 with the second connecting member 18 . A fourth brake B4 is engaged to connect the fourth planetary member sun gear 16 with the transmission housing 21 in order to prevent rotation of the fourth planetary row member sun gear 16 relative to the transmission housing 21 . A fourth gear ratio is thus established between the input shaft 22 and the output shaft 23 .

The fifth gear is established, the first clutch C1 and the fourth brake B4 are engaged. Specifically, the first clutch C1 is engaged to connect the input shaft 22 and the first connecting member 17 . A fourth brake B4 is engaged to connect the fourth planetary row member sun gear 16 with the transmission housing 21 in order to prevent rotation of the fourth planetary row member sun gear 16 relative to the transmission housing 21 . Thus, a transmission ratio of fifth gear is established between the input shaft 22 and the output shaft 23 .

When the sixth gear is established, the first clutch C1 and the second clutch C2 are engaged. Specifically, the first clutch C1 is engaged to connect the input shaft 22 and the first connecting member 17 . The second clutch C2 is engaged to connect the input shaft 22 with the second connecting member 18 . Thus, a transmission ratio of six gears (ie, direct gear) is established between the input shaft 22 and the output shaft 23 .

The seventh gear is established, the first clutch C1 and the first brake B1 are engaged. Specifically, the first clutch C1 is engaged to connect the input shaft 22 and the first connecting member 17 . The first brake B1 is engaged to connect the second connecting member 18 with the transmission housing 21 in order to prevent rotation of the second connecting member 18 relative to the transmission housing 21 . As a result, a transmission ratio of seven gears is established between the input shaft 22 and the output shaft 23 .

Eighth gear is established, the first clutch C1 and the second brake B2 are engaged. Specifically, the first clutch C1 is engaged to connect the input shaft 22 and the first connecting member 17 . The second brake B2 is engaged to connect the first planetary carrier 3 with the transmission housing 21 in order to prevent the first planetary carrier 3 from rotating relative to the transmission housing 21 . Thus, an eighth gear ratio is established between the input shaft 22 and the output shaft 23 .

Table 1 shows the truth table of the transmission ratio, the speed ratio step and the engagement state of the torque transmission device of each gear for each gear of the eight-speed transmission.

In the figure: X means engaged and torque is transmitted O means engaged but no torque is transmitted.

Claims (1)

1. An eight-speed transmission, which includes an input shaft, an output shaft, a planetary gear row, a connecting member and a torque transmission device, and the above-mentioned components are all arranged in the transmission housing, and the planetary gear row includes a first planetary gear row, a second planetary gear row, and a second planetary gear row. The planetary gear row, the third planetary gear row and the fourth planetary gear row, each planetary gear row includes a sun gear, a planet carrier, a planetary gear and a ring gear; the connecting member includes a first connecting member, a second connecting member, a second connecting member Three connecting members and a fourth connecting member; the torque transmission device includes a first clutch, a second clutch, a first brake, a second brake, a third brake and a fourth brake, and it is characterized in that: the first connecting member will The sun gear of the first planet row and the sun gear of the second planet row are interconnected; the second connecting member connects the ring gear of the first planet row, the planet carrier of the second planet row and the The ring gear is continuously interconnected; the third connecting member interconnects the ring gear of the second planet row and the planet carrier of the fourth planet row; the fourth connecting member interconnects the planet carrier of the third planet row interconnected with the ring gear of the fourth planetary row; the first clutch interconnects the input shaft and a second connecting member, the second clutch interconnects the input shaft and a first connecting member; The first brake interconnects the first connecting member and the transmission housing, the second brake interconnects the planet carrier in the first planet row with the transmission housing, and the third brake interconnects the the second connecting member interconnects the transmission housing, the fourth brake interconnects the sun gear of the fourth planetary row and the transmission housing; The sun gear of the third planet row is always connected with the input shaft, and the planet carrier of the fourth planet row is connected with the output shaft.